Okay, I see now that you are comparing gas with a heat pump!
If the run load amps is rated for 17 amp draw, it should never be operated above 17 amps. However, if you put 55° water through the condenser instead of 95° air, the run load amps will be below 17. No?
Most geothermal units operate below the rate amperage drawn consistently.
I believe our misunderstanding here is that we are comparing different units designed completely different from one another.
When we discuss compressor load and lifespan only, a DX heat pump runs under much less power consumption and load in the winter than a geothermal unit in the heating mode. Therefore, a geothermal unit is under greater strain in the wintertime and will wear out quicker.
However, if we are looking at power savings, the geothermal does not use auxiliary heat or a defrost cycle like the DX heat pump. So the DX heat pump consumes more power.
Now when we look at the really big picture (total money spent), we have to look at increased equipment costs, increased maintenance costs versus overall life expectancy of the equipment when we look at the bottom line.
As you are pointing out, there may not be much of a difference in total lifespan (depending on the equipment compared).
We’re just not viewing this issue from the same side of the fence!